Out on the northern Nevada high desert, a little-known Houston company is developing an energy source that could revolutionize what has been long on promise but short on delivery–turning the intense heat deep below our feet into useful terrestrial heat and electricity. Geothermal energy, carbon dioxide free, 24/7. MIT Technology Review has called it “like a giant underground battery.”
Adapting technology that revolutionized the U.S. oil and gas industry 15 years ago — horizontal, directional drilling — Fervo Energy last year ran a successful pilot project at its Nevada site.
Last week (Feb. 29), Oklahoma-based oil and gas independent Devon Energy led a $224 million funding consortium to invest in Fervo as it moves toward commercial operation. The Devon funding group includes Japan’s Mitsubishi Heavy Industries. At the same time, the Department of Energy awarded Fervo $25 million.
Fervo explains, “We employ precision directional drilling technology to drill horizontally in geothermal reservoirs. This enables us to drill multiple wells from a single location, dramatically lowering our surface footprint and reducing drilling risks. Horizontal drilling also facilitates greater access to geologies that were previously challenging to reach, increasing the total resource potential for geothermal energy.”
After drilling into the earth’s hot rocks, Fervo then injects water into the wells and lets it sit and get hotter, generate tremendous pressure. When plant operators release the valve holding the water back, it surges out for hours on end.
MIT’s technology review wrote that Fervo’s approach suggests “Fervo can create flexible geothermal power plants, capable of ramping electricity output up or down as needed. Potentially more important, the system can store up energy for hours or even days and deliver it back over similar periods, effectively acting as a giant and very long-lasting battery. That means the plants could shut down production when solar and wind farms are cranking, and provide a rich stream of clean electricity when those sources flag.”
Former oil industry executive and Fervo founder Tim Latimer said, “We know that just generating and selling traditional geothermal is incredibly valuable to the grid, But as time goes on, our ability to be responsive, and ramp up and down and do energy storage, is going to increase in value even more.”
As Fervo moves forward, a Massachusetts startup, Quaise Energy, has landed $40 million in venture capital for demonstration of a deep drilling technology based directly on MIT research. The technology is unconventional, based more on the physics of the so far feckless fusion search rather than Fervo’s adaptation of oil field mechanics.
The Quaise technology using a focused, extremely high-temperature beam, could allow drill bits to dig some 12 miles deep into the earth where temperatures are the greatest. That’s miles, not feet. Superdeep, superhot. According to a Quaise news release, “At these depths, geothermal energy is power-dense, virtually unlimited, and available everywhere on the planet.”
While unconventional in the world of geothermal energy, the basis of Quaise’s deep dive into the earth of is a device used for decades in manufacturing and research, a focused microwave emitter called as “gyrotron.”
Paul Woskov, a researcher at MIT’s Plasma Science and Fusion Center, notes that gyrotrons “are commercially available. You could place an order with a company and have a system delivered right now — granted, these beam sources have never been used 24/7, but they are engineered to be operational for long time periods.” Woskov is an informal advisor to Quaise.
According to Woskov, while gyrotrons “haven’t been well-publicized in the general science community, but those of us in fusion research understood they were very powerful beam sources — like lasers, but in a different frequency range. I thought, why not direct these high-power beams, instead of into fusion plasma, down into rock and vaporize the hole?”
If the technology works, it could be a complete game changer. It would be possible to drill down into the source of the most intensive underground heat on the site of abandoned steam-electric power plants, using heat from the boreholes to make steam and use the existing steam turbine-generators.
“This will happen quickly once we solve the immediate engineering problems of transmitting a clean beam and having it operate at a high energy density without breakdown,” Woskov told MIT News. “In five or six years, I think we’ll have a plant running if we solve these engineering problems. I’m very optimistic.”
While the geothermal horizon looks promising, resting on unconventional but available technology, conventional geothermal continues to have problems. Most recently, the Alaskan city of Unalaska (pop. 4,254), aka Dutch Harbor, in the center of the Aleutian Island chain, rejected new terms for a long-delayed 30-MW geothermal project using heat from an active volcano.
Alaska Public Media reported that the city council on Feb. 27 turned down a rate hike proposed by the developers of the $200 million Makushin geothermal project, Ounalashka Corp. and Chena Power. The statewide radio network said it was the fourth time the city had rejected a proposal to change the power purchase agreement with the developers. “While council members all voiced general support for the project, the consensus was that they had lost confidence that the project would be completed on a reasonable timeline.”
—Kennedy Maize